Charge-Coupled Devices (CCDs) have been widely known as solid-state imaging devices for taking images of incident light, and among the CCDs, an EM-CCD (Electron Multiplying-CCD) that enables taking an image of weak light has been known. This type of solid-state imaging device includes, in addition to an imaging area that includes a plurality of photodiodes or the like and generates charges according to the amount of incident light and an output register unit that reads out the charges of the imaging area, a multiplication register unit that multiplies the read-out charges, and enables taking an image of weak light by using a charge multiplication effect of the multiplication register unit. This type of solid-state imaging device has been disclosed in Patent Literatures 1 and 2.
The solid-state imaging devices described in Patent Literatures 1 and 2 control the multiplication factor (gain) of the multiplication register unit based on an output of the multiplication register unit, that is, perform feedback control of the multiplication factor of the multiplication register unit.